The achievement of a perfectly, or near perfectly, flat surface on a concrete or other hard surface is particularly important from a viewpoint of function and safety in the case of commercial or industrial buildings and from the viewpoint of satisfying minimum floor flatness specifications on new construction projects. In addition, the perfectly, or near perfectly, flat surface may also be important from the viewpoint of aesthetics in the case of diamond polished floors for all types of buildings.
In the case of commercial and industrial buildings, it is important to produce a floor which is significantly flat to enable forklift trucks to pass safely and efficiently over the floor. The significantly flat floor allows forklift trucks to remain sufficiently level even when heavily loaded, so as to avoid spilling loads or hitting pallet racks in a narrow aisleway due to sway of the lift truck mast. In addition, it is often necessary to provide a significantly flat floor (and perhaps also level) for the mounting of certain types of machinery or industrial equipment.
In the case of diamond polished floors it is highly desirable to produce a flat floor at the very beginning of the grinding and polishing process from the standpoint of two different aesthetic considerations. Firstly, when a typical floor grinder is placed and run on a floor which has an inherent wavy or rippled surface, undesirable gouges or coarse scratches can be formed in the low areas between the high points, or ridges, of the waves as the grinder dips into the low areas. Once formed, these pronounced scratches are extremely difficult to remove in subsequent grinding steps. Secondly, unless the waviness is removed and the floor flattened to an adequate extent, the waves will be extremely visible and very unpleasant in appearance once the floor is brought up to a high polish. In such a case, the waves often resemble a badly warped mirror.
Currently, these surface waves can be selectively removed using conventional dual rotating planetor style or fixed rotating spindle type grinders by a combination of methods. These methods include: (1) using a large-headed grinder compared to the wavelength of the ripples; (2) running the grinder only along the center line of the ridges of the waves until they are milled off flush to the surrounding low areas, and (3) using long straight edges to periodically check the progression of the grinding and flattening operation. These methods are difficult since these methods are laborious, labor intensive and time consuming which results in a method that is also costly. The methods to flatten the surface waves become even more difficult as the wavelength of the ripples increases. While it is possible to achieve a fairly flat floor in most cases by means of applying very good techniques, well suited equipment and extremely skilled workmen, most floors are currently produced which are not substantially perfectly flat, just improved somewhat by means of primarily flattening the shorter wavelength ripples.
As diamond polished floors have been gaining considerably in popularity in recent years because they are extremely durable, very cost effective, require very little maintenance, capable of being very attractive, and finally, have a very high “green” rating (i.e., a very small environmental impact), there exists a need for an effective flattening device which is able to do precision quality flattening.